1. Field of the Invention
The present invention relates generally to the field of ureteral stents and catheters. More particularly it relates to a ureteral catheter/stent combination that allows for continuous lavage of the upper urinary tract.
2. Description of the Prior Art
To date, medical therapy for pathologic conditions of the upper urinary tract has been less successful than treatment by surgical means. The relative resistance of the upper urinary tract to medical treatment is due both to the nature of the system itself and the nature of the common pathologic conditions that affect it. The upper urinary tract is, first of all, relatively inaccessible. In addition, the flow of urine from the kidney to the bladder cannot be impeded for any extended period of time without resultant kidney damage. Furthermore, medical management of pathologic conditions of this system, as, for example, chemolysis of kidney stones, may require prolonged application of agents. Nevertheless, finding a reliable and well-tolerated means of applying medicaments to the upper urinary tract is a worthwhile aim. Such a means could enhance the treatment of diseases affecting this system by providing a substitute for or a complement to the use of surgical techniques.
Various solutions have been attempted to meet the challenge of providing for medical treatment of conditions of the upper urinary tract. Prior art means that have been tried to achieve this goal have been found to have significant drawbacks. Oral medications such as potassium citrate have been used to treat conditions of the upper urinary tract by alkalinizing the urine in order to effect dissolution of uric acid kidney stones. Generally however, the effectiveness of oral medications is hampered because of dose limitation, the potential for systemic side effects, and patient non-compliance with regimens. Various stents and catheters are in common use, some using balloons, but they have been found by the applicants to have problems in delivery of medicaments to the renal pelvis and/or drainage of urine and other resulting fluids. Problems to date have included the inability of achieving an endurologic means of delivering adequate quantities of medication to the renal pelvis for periods of time sufficient to achieve the desired therapeutic result.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide an improved catheter system for delivering medicaments to the renal pelvis.
It is another object of the present invention to provide an improved medication-delivering catheter system that improves drainage from the renal pelvis.
A further object of the invention is to provide an endurologic means of delivering adequate quantities of medication to the renal pelvis.
It is yet another object of the present invention to provide a such an endurologic medication delivery means for periods of time sufficient to achieve the desired therapeutic result.
The above and other objects and advantages, which will be apparent to one of skill in the art, are achieved in the present invention which is directed to, in a first aspect, a urethral/ureteral catheter system comprising a urethral catheter infusion tube section adapted to extend through a urethra for infusion of a liquid and a urethral catheter drain tube section adapted to extend through a urethra for drainage of a liquid. There is also provided a ureteral catheter tube section adapted to extend through a ureter into a kidney and having a first tube portion for infusion of a liquid connected to the urethral catheter infusion tube section, and a second tube portion for drainage of a liquid. A curved, flexible tube portion at an end of the ureteral catheter section extends into the renal pelvis. The ureteral catheter tube section has a plurality of drain openings along a side wall thereof for receiving fluid to be drained from the kidney and a plurality of infusion openings along a side wall thereof for infusing fluid into the kidney.
Preferably, the ureteral catheter tube section drain openings extend a greater distance from the end of the ureteral catheter section than the ureteral catheter tube section infusion openings. The ureteral catheter tube section drain openings are also preferably further disposed on the ureteral catheter tube section adapted to extend through the ureter. The drain portion and the infusion portion of the ureteral catheter tube section may extend along side each other along at least a portion of the length thereof.
More preferably, at least some of the ureteral catheter tube section drain openings increase in size with increasing distance from the end of the ureteral catheter section, and at least some of the ureteral catheter tube section drain openings decrease in spacing with increasing distance from the end of the ureteral catheter section. The curved, flexible tube portion at an end of the ureteral catheter section may form a coil shape.
The ureteral catheter tube section first tube portion may have infusion openings only in the portion extending into the renal pelvis. Preferably, the ureteral catheter tube section second, drainage tube portion has a larger flow diameter than the ureteral catheter tube section first, infusion tube portion, and the end of the ureteral catheter section is tapered inward. At least some of the ureteral catheter tube section infusion openings may be closer to the end of the ureteral catheter section than the ureteral catheter tube section drain openings.
In a preferred embodiment, the ureteral catheter tube section second, drainage tube portion terminates at a lower end prior to the connection between the ureteral catheter tube section first, infusion tube portion and the urethral catheter infusion tube section. The ureteral catheter tube section second, drainage tube portion may have an opening at the lower end prior adapted to receive a guidewire for insertion along the length of the ureteral catheter tube section second, drainage tube portion.
In another aspect, the present invention is directed to a method of treating the upper urinary tract of a mammal having a urethra extending to a bladder and a ureter extending from the bladder to a kidney. The method comprises initially extending a catheter system into the upper urinary tract, the catheter system having a urethral catheter infusion tube section extending through the urethra for infusion of a liquid; a urethral catheter drain tube section extending through the urethra for drainage of a liquid; a ureteral catheter tube section extending through a ureter into the kidney and having a first tube portion for infusion of a liquid connected to the urethral catheter infusion tube section, and a second tube portion for drainage of a liquid. The method then includes flowing a fluid into the kidney through the urethral catheter infusion tube section and the ureteral catheter first, infusion tube portion, and, simultaneously with the flowing of the fluid into the kidney, draining fluid from the kidney through the urethral catheter drain tube section and the ureteral catheter second, drain tube portion. Preferably the infusion fluid comprises a therapeutically effective liquid for treating the kidney.
In practicing the method of the present invention, the ureteral catheter tube section has a drainage opening substantially sealed by walls of the uretero-pelvic junction prior to flowing the fluid into the kidney. After flowing the fluid into the kidney, these walls are dilated to expose the drainage opening at the uretero-pelvic junction.